Although PYR products were used in both rice farms and residential areas, the concentrations of PYR metabolites were not significantly different between the participant groups. This finding suggests that PYR use in rice farms was not a primary source of PYR exposure, but rather, PYR used in households may be considered as a main source of exposure. Based on the type and frequency of use of PYR products in households, the levels of PYR exposure were slightly different between participant groups. Participants living in the aquacultural area who used insecticide spray products (mostly containing permethrin and cypermethrin)1 more often had slightly higher PYR metabolite concentrations than participants living in the rice farming area. This finding confirms that PYR found in insecticide products used in households contributes more significantly to the level of PYR metabolites in participants than those PYR-containing products used in rice farms.